The southern United States is full of elderly Canadians nicknamed 'snowbirds' because they fly south for winter.

Hong Kong has a large population of Canadians, and some, myself included, prefer the warmth of Hong Kong to Canada's frigid winters. We go wherever we find life comfortable, and stay away from places we don't like.

Animals in Canada are no different. They will live wherever they can find food and suitable weather. Now climate change is making the Arctic warmer and suitable for some wildlife that has previously remained in the south. As new animals slowly spread north, they challenge the region's existing wildlife for food, hunting grounds and breeding areas.

When I was in the Arctic last summer, we learned about the Arctic fox, which is now classified as an endangered species. On Herschel Island, I met two scientists who were studying not only Arctic foxes, but also red foxes, which normally live further south. The scientists wanted to learn about the impact of the northern migration of red foxes.

Most areas of the Arctic are too cold for trees. However, climate change is causing the snow-line to recede further north, increasing the area within which trees can grow. Red foxes like to live around trees, so they are moving north as well.

Artic foxes have evolved to be able to live comfortably in the cold, treeless Arctic. They have round, compact bodies to reduce heat loss, and their muzzle, ears, and legs are short, which also conserves heat. Their paws have hair on them to give them grip on the snow and ice. But it's their thick fur that protects them the most. In the winter this fur turns a beautiful white, which matches the snow and helps them hide from other animals.

Arctic foxes eat mostly lemmings, a type of mouse. But as this is also a favourite food of the red fox, they now have a competitor. The red fox is slightly larger and will steal the den of an Arctic fox or even kill them as they compete for territory.

So who cares if red foxes move into Arctic fox territory? We should because we could become victims of the same process. Next week I'll tell you how climate change could make some cities unsuitable for humans, forcing us to find new homes, just like the foxes.